Numerical Simulation and Experimental Study on Flame Auxiliary-heated Friction Stir Welding

Friction stir welding technology was still limited by the lifetime of the stir tool in welding materials with high melting point.The tool pin undergoes serious shear and frictional wear in friction stir welding process.Preheating the workpiece can soften the material to be welded,which is one of the effective ways to improve the life of the tool.The numerical simulation and experimental study on the friction stir welding of Q235 steel with auxiliary oxygen-propane flame heating were conducted.Heat transfer model including such two heat sources as flame and friction was established.Software ANSYS was used to analyze the heat transfer process.The temperature distribution was acquired.The microstructure as well as the hardness of heat affected zone,heat-mechanical affected zone and stir zone,was analyzed.FSW experiments were carried out to verify the simulation results.The simulation results are in good agreement with the experimental results.